LAREDO, Tex. — The young children, two American, two Mexican, walked toward one another, nearing the center of the Juarez-Lincoln International Bridge. The short stretch of road over the Rio Grande has long connected this Texas border town with its sister city, Nuevo Laredo, Mexico, and about 15,000 vehicles enter the United States on it each day. But traffic came to a halt on this holiday weekend for this moment.

The children, ages 7 to 9 and dressed in colonial regalia, wrapped their arms around one another.

Their “abrazo” — Spanish for “embrace” — marked the 120th time in the cities’ history that the pair celebrated George Washington’s Birthday, part of a month-long party that includes parades, an air show, a debutante ball and a carnival, drawing about 400,000 people. It is a celebration of Americanness that began half a century after Laredo joined the United States following the Mexican-American War, but it is now a show of North American unity.

Members of the Texas Sons of the American Revolution walk to the bridge ceremony in Laredo. (Ray Whitehouse for The Washington Post)

The two cities might as well be one. They share an economy, separated by hours from the nearest metropolis on either side of the border. They share a culture, with restaurants such as Laredo’s El Meson de San Agustin serving chicken cordon bleu on the same menu as enchiladas Mexicanas. More than 95 percent of Laredo’s residents are Latino and carry out life in a fluid stream of English-Spanish bilingualism.

But the annual birthday party for the nation’s first president this year is set against a new backdrop created by Donald Trump, the nation’s 45th — the prospect of a border wall and tougher immigration rules.

“Here in Laredo, Texas, we’re very unique. We’re ‘la frontera,’ the border area,” Mayor Pete Saenz told reporters after the embrace Saturday, a tradition that began in the 1960s, when it was far easier for the residents of Nuevo Laredo to cross the river into the United States. “And we want peace and we want mutual respect, and we’re doing everything possible to communicate that message to everyone, especially in Washington.”

Laredo Mayor Pete Saenz. (Ray Whitehouse for The Washington Post)

Saenz hosted Trump when he visited Laredo as a candidate in July 2015, soon after Trump labeled Mexican immigrants criminals and rapists in a speech announcing his presidential bid. Many people here think Trump’s rhetoric and actions — including his executive orders to construct a border wall and increase the speed of deportation of undocumented immigrants — are deterring Mexican customers from coming over.

Sandra Bernal, 37, who works at El Meson de San Agustin, her father’s restaurant, said she is grateful her family’s business remains busy; a number of neighbors in downtown Laredo, where Spanish-language music blares from storefronts hawking clothing, perfumes and other goods, are seeing decreased sales.

Miguel Conchas, president of the Laredo Chamber of Commerce, thinks the business lull may be linked to Trump in other ways, too: “When comments are made about the border wall or eliminating NAFTA, it affects the peso,” he said, noting that when the currency weakens, fewer Mexicans want to spend their money in the United States.

That’s no small matter for Laredo, a city of 250,000 where the city’s retail merchants — from small shops to an outlet mall overlooking the Rio Grande set to open in March — draw 40 percent of their sales from Mexican shoppers, according to Conchas. And more important, with Laredo being the largest inland port along the U.S.-Mexico border and a major hub for export-import businesses — Laredo’s five border crossings accounted for $204 billion in international trade in 2015 — any changes to the North American Free Trade Agreement would have a direct effect on the city.

But the potential effect is also cultural, especially for the many families that span the border and commuters on each side who traverse daily to their jobs. Mexican students who attend Laredo’s Texas A&M International University cross paths with busi­ness­peo­ple and others headed south.

“We all have somebody that lives on the other side that we’re in close contact with,” said Jesse Gonzalez, president of the International Good Neighbor Council, which is responsible for the abrazo event. “For some, it’s family, and for others, it’s business, and for others, it’s friends.”

Wearing an elaborate brown coat trimmed in lavish golden floral appliqué, an outfit no doubt far sparklier than anything George Washington actually wore, Doug Howland practiced Thursday night for his leading role in this year’s pageantry as one of America’s Founding Fathers.

The dress rehearsal was for the Society of Martha Washington Colonial Pageant and Ball, an affair in which a handful of Laredo debutantes, the majority of them Latina, pretend to be one of Martha Washington’s colonial cohorts. They come out to society in elaborately festooned, frill- and beadwork-covered gowns complete with flowing hoop skirts; the dresses can weigh nearly 100 pounds and reportedly can cost tens of thousands of dollars.

As this year’s 15 girls, known as “Las Marthas,” readied for the event, Howland, a retired businessman from the construction industry, said the community is wondering about Trump’s next move.

“Right now I think we’re all kind of waiting to see how it’s going to play out,” said Howland, 66. “I honestly think that a lot of it is rhetoric and negotiating strategies more than anything else, but it does have people worried. I can tell you that for sure.”

For 17-year-old debutante Andrea Martinez, who was dressed in a deep-fuchsia gown, the abrazo signifies a moment of international unity.

“I think it’s great when we do that hug, because it represents the bond of two countries coming together,” she said. She found the thought that a wall could cleave her community anytime soon incredulous. “The closest thing happening to our border right now is the new mall.”

Madison Danielle Lozano walks around the stage at the Society of Martha Washington Colonial Pageant and Ball in Laredo on Friday. (Ray Whitehouse for The Washington Post)